General Flashcards
Ions to know
NO3 –, CO3 2–, SO4 2–, OH–, NH4 +, Zn2+ and Ag+
metal + water
metal hydroxide + hydrogen
metal + acid
salt + hydrogen
metal hydroxide + acid
salt + water
metal carbonate + acid
salt + water + carbon dioxide
what is a thermal decomposition reaction?
breaking molecules down by heating them
what is a base?
a proton acceptor
what is an alkali?
a soluble base
releases OH- ions in aqueous solution
why do isotopes have the same chemical properties?
because they have the same number of electrons in their outer shell
How do you make a standard solution?
- Dissolve an exact mass of the solute in a solvent.
- Make the solution up to an exact volume.
Uncertainty for a specific instrument reading
Uncertainty in a reading for a specific instrument is said to be plus or minus half of the smallest division.
what is a covalent bond?
the strong electrostatic attraction between a shared pair of electrons and the nuclei of the bonded atoms
atom economy
molar mass of desired products / molar mass of all products
x 100
what is an acid?
releases H+ ions in aqueous solution
percentage yield
actual amount (in mol) of product / theoretical amount (in mol) of product x 100
what is a salt?
the product of a reaction in which the H+ ions from the acid are replaced by metal or ammonium ions.
first ionisation energy
the energy taken to remove 1 mole of electrons for 1 mole of gaseous atoms to produce 1 mole of gaseous 1+ ions
what do hydrogen bonds act between?
an electronegative atom with a lone pair of electrons e.g. O
a H atom attached to an electronegative atom
why is ice less dense than water?
H bonds hold lattice apart in an open lattice structure.
So the molecules in ice further apart than in water.
Solid ice is less dense than water and it floats.
